Will Jacoby Ellsbury Ever Regain His Power?

In 2011, Jacoby Ellsbury was the best player in Major League Baseball. He finished the year with a .321 average, 32 home runs and 39 steals while also playing stellar defense (16 UZR, fourth overall in MLB) in center field. His 9.1 WAR led the majors, and his all-around season was quite the pleasant surprise for those who had been following his career since he was drafted out of Oregon State in 2005.

After hitting .313/.390/.426 with nine home runs and 103 stolen bases over nearly 1,000 minor league at-bats, it looked like he would continue that type of production once he reached the majors. As a 23-year-old in 2007, Ellsbury hit .353 in 33 games after a late-season call-up, and continued that success in the World Series. In Boston’s four-game sweep of Colorado, he hit .438 with four doubles.

For the next two years, Ellsbury solidified his place as the Sox’s everyday center fielder. In 2008-2009 he averaged .291/.346/.405 with eight home runs and 60 stolen bases per year. He accumulated 6.2 WAR over the two seasons—not quite All-Star level, but definitely the production you’d want from someone anchoring a team’s lineup at the leadoff spot.

After a lost 2010, though, during which he played only 18 games because of a rib injury, Ellsbury emerged as a power threat to start the 2011 season. His four home runs in April were the most of any month in his career, and his seven doubles tied for second. And when the summer months hit, Ellsbury heated up like never before. In 69 games after the All-Star break, he hit 21 home runs, had 56 RBI and had a .625 slugging percentage.

Any Sox fan following the team that season can tell you that seemingly every time Ellsbury came up with the game on the line, he came through with a clutch hit. In August, for instance, he had back-to-back walk-off hits, the second night a walk-off home run. Jacoby finished fourth in the majors in FanGraphs' clutch statistic, which measures “how much better or worse a player does in high-leverage situations than he would have done in a context-neutral environment.”

Unfortunately, Sox fans were robbed of an encore performance after Ellsbury was limited to 74 games following a shoulder injury in 2012. When he returned, he clearly wasn’t the same player, as his .271/.313/.370 line suggested. The verdict on whether Ellsbury could repeat his 30-homer output would have to come in 2013.

So far, in 29 games—just under a sixth of the season—Ellsbury has one home run. His slugging percentage sits at .402, and he’s stolen 12 bases so far—right on pace for his 2008-2009 numbers. It seems that he has reverted back to performing as he did when he first came up to Boston. After stealing just 11 bases in the second half of the 2011 season, he’s already surpassed that total four games into May.

His start to this season brings up the question: Was 2011 just an aberration, or does Jacoby Ellsbury have the potential to hit 30 home runs once again?

Batted Ball

Ellsbury’s batted ball rates, which are in the table to the right, explain some of his variation in power. His 2013 numbers—line-drive percentage, ground-ball percentage and fly-ball percentage—line up almost exactly with his career rates.

The same can’t be said in 2011, though, when he had a career-high line-drive percentage, a career-low ground-ball percentage and his second-highest fly-ball percentage. Throughout his career, Ellsbury has hit .682 on liners, .251 on fly balls and .255 on grounders, but in 2011, he hit .344 on fly balls.

There’s more evidence that shows Ellsbury hit with much more authority in 2011 than he has in any point of his career. His HR/FB ratio was 16.7 percent, despite him never having a full season of over 7 percent. But that figure wasn’t the case of Ellsbury being lucky by having a large number of home runs barely get out of the park.

Ellsbury’s average home run distance in 2011 was 398.6 feet, higher than the MLB average of 396.3. He had only four “just enough” home runs—described by Home Run Tracker as home runs that “cleared the fence by less than 10 vertical feet, OR that landed less than one fence height past the fence.” That tied for 131st in baseball; the leader, Miguel Cabrera, had 16.

The players at the top of the home run leaderboard each season tend to have a HR/FB ratio of 18-23 percent and a fly-ball rate of 35-50 percent. Out of the 23 players to reach 30 home runs in 2011, Ellsbury ranked second-to-last in fly-ball percentage at 34.1 percent and 17th in HR/FB ratio.

Most of these players have a proven track record of hitting at those rates. Take Cabrera for example: The 2012 Triple Crown winner had a HR/FB ratio in the range of 18.3-19.8 percent from 2007-2011. When he jumped to 23 percent in 2012, Cabrera set a career high in home runs.

If Ellsbury had other years during which he had rates similar to those he reached in 2011, there’d be more hope that he could duplicate that 30 home run pace. But considering he has not come close to the 16.7 percent HR/FB ratio before or after his near-MVP campaign, it seems unlikely he’ll reach that number again in the years to come.

Pull Happy

Of the 32 home runs he hit in 2011, Ellsbury pulled 26 of them and hit a mere two to the opposite field. That’s a strong split, even for a pull hitter—something Ellsbury’s not known to be.

Above is a comparison—provided by Baseball Analytics—of Ellsbury’s slugging percentage by pitch location in 2011 and 2012. It’s as big of a one-year difference that you’ll find for an MLB player.

In 2011, Ellsbury crushed pitches over the inner half of the plate, especially those in the lower third of the strike zone. In 2012, he just could not do the same with those pitches. It seems he lost the ability to pull balls for power between the 2011 and 2012 seasons.

The pitch types he was thrown were consistent for 2011 and 2012: 61 percent fastballs, 10 percent sliders and 5 percent cutters. The only major difference is that Ellsbury was thrown more changeups and fewer curveballs in 2012 than 2011—about a 2 percent trade-off.

The biggest disparity is how he’s hit these pitches. In 2011, he hit for 1.43 fastball runs above average per 100 pitches, which ranked top 15 in the American League. That number has sunk to .17 in 2013, which is lower than his career average of .54. This likely has to do with his inability to hit those fastballs inside for power. The numbers don’t suggest pitchers are throwing to him any differently, just that his performance has declined from his 2011 peak.

The difference between 2009 Jacoby and 2011 Jacoby is likely the difference between a Michael Bourn-type deal (five years, $60 million) and Josh Hamilton’s contract (five years, $125 million).

Perhaps that’s the silver lining to his low power numbers: The Sox may now have enough money to sign him when he becomes a free agent at the end of the season.

Having 30-home run power at the top of the lineup is great, but maybe having the best fielding outfield in the majors—once Jackie Bradley is ready—is even better.

Stephen Sikora is a former Red Sox featured columnist and current contributor to Bleacher Report. He's a junior at Boston College and also writes about BC sports for his school's student newspaper, The Heights.